Our previously proteomics study using a cellular model of SCA17 has revealed reduced expression of heat shock 70 kDa protein 5 (HSPA5) [8], a major endoplasmic reticulum (ER) chaperone and master regulator of unfolded protein response (UPR) [9], suggesting that impaired protein folding in ER may contribute the cell dysfunction of SCA17. This evidence concerns the gene HSPA5 and spinocerebellar ataxia type 17.